Multi-window type display device

ABSTRACT

Disclosed herein is a multi-window type display device provided with display units each of which has a display body operated or moved to appear in its display window by means of a permanent magnet which is stably moved by attraction and repulsation forces created electro-magnetically, said display body being irradiated by only one light source common with all the display bodies.

United States Patent 1 1 Watanabe et al.

m1 3,792,540 Feb. 19, 1974 MULTl-WINDOW TYPE DISPLAY DEVICE Inventors: Akimasa Watanabe; Toshio lchikawa; Shigenari Azuma, all of Nagoya, Japan Assignee:

Aiphone Kabushiki Kaisha (Aiphone Co., Ltd.), Aichi-ken, Japan Filed:

Nov. 29, 1971 Appl. No.: 202,844

Foreign Application Priority Data Dec. 3, 1970 Dec. 3, 1970 Aug. 19, 1971 Aug. 19, 1971 u.s.c|. lnt.Cl.

Japan 45/120768 Japan 45/120769 Japan 46/74464 Japanm, 46/74465 .(40/28 C, 40/130 E, 340/373 G09f 11/00 Field of Search 40/28 R, 28 C, 52 R, 61 R, 40/62, 65, 106.45, 130B, 132 R; 335/234, 272; 340/372, 373, 376

play bodies.

[56] References Cited UNITED STATES PATENTS 3,422,426 1/1969 Bailey et al. 340/373 2,680,243 6/1954 Drathschmidt... 340/373 X 2,893,148 7/1959 Figman 40/132 R 2,179,792 11/1939 Lappin 340/373 3,530,454 9/1970 Zocholl 335/234 X Primary Examiner-Jerome Schnall Assistant Examiner-Vance Y. Hum Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [57] ABSTRACT Disclosed herein is a multi-window type display device provided with display units each of which has a display body operated or moved to appear in its display window by means of a permanent magnet which is stably moved by attraction and repulsation forces created electro-ma gnetically, said display body being irradiated by only one light source common with all the dis- 2 Claims, 10 Drawing Figures PATENTEB FEB] 9 I974 summer's AKIMASA WATANABE,

TOSHIO ICHIK AWA and SHIGENARI AZUMA,

INVENTORs BY MMWW PATENTEDFEBI 9 I974 SHEET 2 0F 3 FIG3 AKIMASA WATANABE, TOSHIO ICHIKAWA and SHIGENARI AZUMA,

INVENTOR 3 BY Us ATTORNEY 5 MULTI-WINDOW TYPE DISPLAY DEVICE BACKGROUND OF THE INVENTION The present invention relates to a multi-window type display device which is effective and simply for a number of displays.

Heretofore, there have generally been two types of display devices of the class disclosed; one is a lamp type display device which utilizes alight, and the other is a magnet type display device which uses an electromagnet. However, the former involves many drawbacks, that is, inferior in economization, low in dependability, and difficult in maintenance and inspection due to the following reaons. The conventional, lamp type display device requires a light source such as a lamp for every display window thereof. When the frequency of use of the lamps is high, the lamps are apt to be broken easily, and even if only one lamp is broken or becomes out of order, the whole display device becomes unserviceable. Furthermore, an electric current flows through the lamps for the time period of the display with the result of a great electric power comsumption.

On the other hand, in the conventional magnet type display device, a display plate is rotated or moved by the utilization of the force of an electro-magnet thereby to display information with letters or colors on the dis-v play plate. However, this type of display device also suffers from disadvantages such that it is hard to see the display from far away or at a dark place, and the display device is apt to cause erroneous operations.

SUMMARY OF THE INVENTION An object of the present invention is accordingly to provide a display device which is simple in maintenance and inspection, in which colored transparent display bodies are operated by respective electro-magnets thereby to appear in respective display windows where displays is to be made, and the display bodies are irradiated by one light source common to all the display bodies whereby the display can be recognized from far off or at a dark place.

The above object and other objects as well as the characteristic features of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawings:

FIG. 1 is a perspective view illustrating an embodiment of the display device according to the present invention;

FIG. 2 is a diagram showing the arrangement of various parts to be assembled with a display panel in the embodiment shown in FIG. 1;

FIG. 3 is a disassembled perspective view of a display unit in he embodiment shown in FIGS. 1 and 2;

FIGS. 4a and 4b are perspective veiws illustrating the external appearances of the display unit shown in FIG.

FIGS. 5a to 5d are diagrams explaining the operation of a permanent magnet in a unit case in the embodiment shown in FIGS. 1 to 4; and

FIG. 6 is a diagram exhibiting a display operation the above-mentioned embodiment.

DETAILED DESCRIPTION OF THE INVENTION With reference now to FIG. 1, there is shown an embodiment, namely, a display device according to the present invention, which comprises a case 1, a display panel 2, display windows 3 opened through the display panel 2, a common light source 4 such as a fluorescent lamp, an transparent entry plate 5, and a milk-white light-shielding plate 6 which is adapted to prevent the light of the fluorescent lamp 4 from directly coming into the eyes of a man.

As shown in FIG. 2, the entry plate 5 and the lightshielding plate 6 are spaced with a support pipe 7 and are mounted on the panel 2 with a female-threaded nut 9 and a male-threaded bolt 8 provided on the panel 2. A display unit 10 is fixedly mounted on a supplementary plate or a unit holder 11 with female-threaded nuts 14 and 15 and male-threaded bolts 12 and 13 which go through mounting hole members 16 and 17 provided on the display unit 10. The unit holder 11 is in turn fixedly mounted on the panel 2 by means of a femalethreaded nut 19 and a male-threaded bolt 18 provided on the panel 2 so that the display unit 11 is fixed on the panel 2.

Referring now to FIG, 3, there is shown disassembled view of the display unit 10, whcih comprises an electromagnet composed of two windings 21 and 22 and a U- shaped iron core the magnetic poles 23 and 24 of which have grooves 25 and 26 in the center of their respective ends and a unit case 27 comprising a top part 28 and a bottom part 29. The bottom part 29 is mounted over the magnetic poles 23 and 24 of the iron core 20. A convex shoulder on step30 is provided on the lower center part of the inside of the bottom part 29, and on the outside of the bottom part 29 an iron piece 31 is provided between the magnetic poles 23 and 24 of the iron core 20.

On the other hand, the top part 28 is provided with the mounting hole members 16 and 17 which are used to mount the display unit 10 on the unit holder 11 as described in connection with FIG. 2. A permanent magnet 34 has a front side 35 and a rear side 36 which are a north pole and a south pole, respectively. The permanent magnet 34 is provided with a sliding piece 37. This sliding piece 37 is made of a thin, nonmagnetic material, and has a rectangular hole 37a at the center'thereof and arms 38 and 39 on the front end thereof. The permanent magnet 34 is inserted in the rectangular hole 37a of the sliding piece 37 so that the sliding piece 37 can follow the movement of the permanent magnet 34. The assembly of thepermanent magnet 34 and the sliding piece 37 is then placed inside the unit case 27. Furthermore, the sliding piece 37 is inserted into a groove 32 provided on the bottom part 29 of the unit case 27. A display body 40 is 'made of a lighttransparent colored material, and has a notch 42 in a part ofits display surface 41, said display body 40 being fixed on arms 38 and 39 of the sliding piece 37 through a slot 33 in the top part 28. Therefore, the display body 40 can operate in cooperation with the movement of the permanent magnet 34. v I

The display unit 10 operates as follows:

Now, lets assume that the permanent magent 34 is initially positioned on the side of the magnetic pole 23 of the U-shaped iron core 20. Under this condition, when the magnetic poles 23 and 24 are magnetized to be a north pole and a south pole, respectively, by flowing an electric current through one of the windings of the U-shaped iron core 20, the permanent magnet 34 is attracted to the magnetic pole 23 and at the same time repulsed by the other magnetic pole 24, because the rear side 36 of the permanent magnet 34 is a south pole as mentioned before, as a result of which the permanent magnet 34 stably remains'at its initial position. Under this condition, even if the flow of current is ceased, the permanent magnet 34 is fixed by its own attraction force to the side of the magnetic pole 23, as shown in FIG. 5a.

Then, when an electric current is made to flow through the other winding 22 in a direction opposite to the direction of the current passed through the winding 21, the magnetic poles 23 and 24 are magnetized into a south pole and a north pole, respectively. As a result, by the repulsion force due to the magnetic pole 23, the permanent magnet 34 floats off the magnetic pole 23 as shown in FIG. Sb and then jumps over the shoulder 30 as shown in FIG. 5c. Furthermore, the permanent magnet is moved to the side of the magnetic pole 24 by the attraction force due to the magnetic pole 24, as shown in FIG. 5d. Under this condition, even if the flow of current through the winding 22 is ceased, the permanent magnet 34 is fixed, by its own magnetic attraction force, to the side of the magnetic pole 24. It goes without saying that the display body 40 is also moved together with the permanent magnet 34, as illustrated in FIGS. 5a to 5d, whereby displaying can be effectively attained through the display windows 3.

The permanent magnet 34 is initially fixed to the side of the magnetic pole 23 of the iron core 20, but when any force such as vibration which is greater than the coercive force of the magnet 34 is -applied to the permanent magnet 34 from outside the display unit 10, the permanent magnet 34 is moved over to the side of the magnetic pole 24. This has been a cause for the erroneous operations of the display unit. However, this drawback is eliminated, according to the present invention, by providing the shoulder 30 on the lower part of the unit case so as to prevent the permanent magnet from movement caused by such external force, that is, to prevent the erroneous operations.

In general, the display panel 2 is made ofa metal such as iron. Therefore,'when the display unit is mounted on the display panel 2, a force of a permanent magnet 34 housed in the unit case 27 acts greatly on the display panel 2, as a result of which it is required to feed a large electric current through the windings in order to operate or move the permanent magnet. This is uneconomical and is one of the drawbacks involved in the conventional display unit. However, according to the present invention this drawback is solved by provision of the iron piece 31 which serves to neutralize the force of the permanent magent 34 which acts on the display apnel 2, and thereby allows the permanent magnet to be moved by a small electric current.

The display device according to the present invention utilizes the operation of the display unit described above. The display unit operates as follows.

The fluorescent lamp 4 is kept in illuminated state at all times regardless of the presence or absence of a display. For display, the display surface 41 and notch 42 of the display body 40 are inserted between the entry plate 5 and the light-shieldingpl'ate 6 thereby to appear in the display window 3, as shown in FIG. 6. If the display body 40 is made of a red transparent plate, we can see only the display body brightened in red. Therefore, the displaywindow having the thus brightened display body is readily distinguished from the other windows not displayed. Furthermore, since we can see the notch 42 brightened in the same color as that of the display window 3, the colored display surface 41 is emphasized in brightness by the effect of the notch, as a result of which the display can be clearly recognized from afar.

The above-described embodiment according to the present invention corresponds to the case in which a two value display is carried out by providing the display unit on the upper side of the display window, but the display units may be provided on the upper and lower sides of the display window or the upper, lower, right and left sides thereof for the display of four or more values.

As is apparent from the above description, according to the present invention, since the fluorescent lamp is kept in a brightened state at all the times, the display can be clearly recognized even at a dark position or even from afar. In addition, the fluorescent lamp has a longer service life than other lamp types, the frequency of replacement of the fluorescent lamp is only once a year or once every two years. In conclusion, the display device according to the present invention is simple in maintenance and inspection, superior from an economical view point, and significant in a practical effect.

We claim:

1. A multi-window type display device, whcih comprises, in combination, a plurality of display windows, a plurality of display units at least one of which is provided at each of said display windows, and one light source common to all the display units and located to the rear of said display units; each of said display units comprising a display body disposed at the rear side of one of said display windows; an electromagnet comprising a U-shaped iron core, the legs of said U-shaped core extending towards said display window and terminating in two pole ends and an energizing winding means adapted to alternately magnetize said iron core in one direction or the other opposite direction such that said two pole ends are always oppositely polarized; a unit case mounted over the surfaces of both poles of said iron core, said'case including a passage and containing therein a permanent magnet, one pole of said permanent magnet facing in the direction of said display window and the other pole of said permanent magnet facing away from said display window, said permanent magent being adapted to be slid along said passage formed in said case from one pole to the other pole of said electromagnet, said passage being provided with a convex shoulder at the center portion of the sliding surface of said passage and protruding towards the interior of said passage, whereby said permanent magent is stopped by said shoulder irrespective of any vibration shock from outside and is made to jump over said eonvex shoulder when said magnet is moved from one pole tip to the other pole tip of said electromagnet in response to the magnetization direction of said electromagnet poles, said case having a slot positioned therein and said permanent magnet being provided with arm means protruding from said case through said slot, said arm means supporting said display body, whereby said display body is, while being irradiated by said light source from the rear side thereof, moved to a position corresponding to the position of said permanent magnet, thereby achieving a display operation.

2. A multi-window type display device as claimed in claim 1 wherein said electromagnet is provided with a magnetizable plate positioned between the poles thereof, thereby to cause effective passing of the magnetic flux produced by said electromagnet. 

1. A multi-window type display device, which comprises, in combination, a plurality of display windows, a plurality of display units at least one of which is provided at each of said display windows, and one light source common to all the display units and located to the rear of said display units; each of said display units comprising a display body disposed at the rear side of one of said display windows; an electromagnet comprising a Ushaped iron core, the legs of said U-shaped core extending towards said display window and terminating in two pole ends and an energizing winding means adapted to alternately magnetize said iron core in one direction or the other opposite direction such that said two pole ends are always oppositely polarized; a unit case mounted over the surfaces of both poles of said iron core, said case including a passage and containing therein a permanent magnet, one pole of said permanent magnet facing in the direction of said display window and the other pole of said permanent magnet facing away from said display window, said permanent magent being adapted to be slid along said passage formed in said case from one pole to the other pole of said electromagnet, said passage being provided with a convex shoulder at the center portion of the sliding surface of said passage and protruding towards the interior of said passage, whereby said permanent magnet is stopped by said shoulder irrespective of any vibration shock from outside and is made to jump over said convex shoulder when said magnet is moved from one pole tip to the other pole tip of said electromagnet in response to the magnetization direction of said electromagnet poles, said case having a slot positioned therein and said permanent magnet being provided with arm means protruding from said case through said slot, said arm means supporting said display body, whereby said display body is, while being irradiated by said light source from the rear side thereof, moved to a position corresponding to the position of said permanent magnet, thereby achieving a display operation.
 2. A multi-window type display device as claimed in claim 1 wherein said electromagnet is provided with a magnetizable plate positioned between the poles thereof, thereby to cause effective passing of the magnetic flux produced by said electromagnet. 